1. Field of the Invention
The present invention relates to a novel alicyclic polyisocyanate compound and a method for producing the same, and a resin obtained using the compound and an optical material comprising the resin.
2. Description of the Related Art
While polyisocyanate compounds are widely used for producing poly(thio)urethane resins and polyurea resins, many reports have been presented in recent years on the application of the polythiourethane resin to optical materials, particularly to plastic lens materials, by noticing that the features of the polythiourethane resins obtained by polymerization of the polyisocyanate compounds and polythiol compounds have high refractive indices.
For example, the polythiourethane resin obtained by allowing xylylene diisocyanate or bisisocyanatomethyl norbornane to react with 1,2-bis[(2-mercaptoethyl)thio]-3-mercaptopropane is reported to be applied to the plastic lens materials (Japanese Patent No. 2621991).
While the optical material described in this Japanese patent above has a high refractive index and heat resistance, the optical materials, particularly the plastic lens materials, have been required to have a high transparency and refractive index as well as higher Abbe number and heat resistance.